I attempt to copy a file first and then to delete the original file,
using Commons/Net.
However, when attempting to perform the deletion I get a

"550 - The process cannot access the file because it is being used by
another process"

error!

Am I doing something wrong? Thx!

The code looks as follows:

COPY FILE
======================

           URL efuFilesDirUrl = new URL(efuFilesDirUrlString);

           BufferedReader in = new BufferedReader(new
InputStreamReader(
                   efuFilesDirUrl.openStream()));

           // Logging on to the FTP server...
           ftpClient.connect(serverName);
           ftpClient.login(username, password);

           // After connection attempt, check the reply code to verify

success
           int reply = ftpClient.getReplyCode();
           if (!FTPReply.isPositiveCompletion(reply)) {
               ftpClient.disconnect();
               throw new EfuException("FTP server refused
connection.");
           }

           // actually back up the files
           ftpClient.changeWorkingDirectory(folder + "/BACKUP");
           {
               String fileName;
               while ((fileName = in.readLine()) != null) {
                   if (!fileName.equals("BACKUP")) {

                       // so, it's an actual file...
                       URL efuFileUrl = new URL(efuFilesDirUrlString
                               + fileName);

                       // ... and thus we need to back it up to
another file
                       // and so that's what we do!
                       ftpClient.storeFile(fileName,
efuFileUrl.openStream());
                   }
               }
           }

           in.close();
           ftpClient.logout();
           ftpClient.disconnect();

SUBSEQUENT DELETE FILE
======================

           URL efuFilesDirUrl = new URL(efuFilesDirUrlString);

           BufferedReader in = new BufferedReader(new
InputStreamReader(
                   efuFilesDirUrl.openStream()));

           // Logging on to the FTP server...
           ftpClient.connect(serverName);
           ftpClient.login(username, password);

           // After connection attempt, check the reply code to verify

success
           int reply = ftpClient.getReplyCode();
           if (!FTPReply.isPositiveCompletion(reply)) {
               ftpClient.disconnect();
               throw new EfuException("FTP server refused
connection.");
           }

           ftpClient.changeWorkingDirectory(folder);

           String fileName;
           while ((fileName = in.readLine()) != null) {
               if (!fileName.equals("BACKUP")) {

                   // so, it's an actual file...
                   // ... and thus we need to delete it
                   // and so that's what we do!
                   ftpClient.dele(fileName);
               }
           }

           in.close();
           ftpClient.logout();
           ftpClient.disconnect();